Fluid separation assembly and fluid separation module

ABSTRACT

A fluid separation assembly having a fluid permeable membrane and a wire mesh membrane adjacent the fluid permeable membrane, wherein the wire mesh membrane supports the fluid permeable membrane and is coated with an intermetallic diffusion barrier. The barrier may be a thin film containing at least one of a nitride, oxide, boride, silicide, carbide and aluminide. Several fluid separation assemblies can be used in a module to separate hydrogen from a gas mixture containing hydrogen.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a Continuation-In-Part of U.S. patent application Ser. No.09/422,505, filed Oct. 21, 1999, entitled “Fluid Separation Assembly.”

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to apparatuses and methods for separationof a desired fluid from a fluid mixture. More particularly, the presentinvention is generally directed to a fluid separation module havingseveral groups of multiple fluid separation assemblies separated byplate members that allows the fluid mixture to pass through the multiplefluid separation assemblies simultaneously.

2. Description of the Invention Background

Generally, when separating a gas from a mixture of gases by diffusion,the gas mixture is typically brought into contact with a nonporousmembrane which is selectively permeable to the gas that is desired to beseparated from the gas mixture. The desired gas diffuses through thepermeable membrane and is separated from the other gas mixture. Apressure differential between opposite sides of the permeable membraneis usually created such that the diffusion process proceeds moreeffectively, wherein a higher partial pressure of the gas to beseparated is maintained on the gas mixture side of the permeablemembrane. It is also desireable for the gas mixture and the selectivelypermeable membrane to be maintained at elevated temperatures tofacilitate the separation of the desired gas from the gas mixture. Thistype of process can be used to separate hydrogen from a gas mixturecontaining hydrogen. Thus, in this application, the permeable membraneis permeable to hydrogen and is commonly constructed from palladium or apalladium alloy. The exposure to high temperatures and mechanicalstresses created by the pressure differential dictates that thepermeable membrane be robust. The palladium and palladium alloy of thepermeable membrane is the single most expensive component of the fluidseparation device, so it is desirable to minimize the amount used in theconstruction of the fluid separation assemblies while still providingfluid separation assemblies that are strong enough to withstand themechanical stresses and elevated temperatures of typical operatingconditions.

One type of conventional apparatus used for the separation of hydrogenfrom a gas mixture employs several fluid separation assemblies in afluid separation module, wherein the fluid separation assemblies areplanar disks that are coaxially aligned and stacked in a verticaldirection. This type of configuration of the fluid separation assembliesis commonly referred to as being a “series operation.” The module has afeed gas inlet, a permeate outlet and a discharge gas outlet. The pathof the gas mixture containing hydrogen travels along the outer surfaceof each of the fluid separation assemblies one at a time, wherein someof the hydrogen of the gas mixture is free to enter the fluid separationassembly by the permeable membranes and is directed to the permeateoutlet and the remaining gas mixture serpentines through the passagewaycontacting each of the remaining fluid separation assemblies one afterthe other. As the gas mixture travels through the passageway, itcontacts the outer surfaces of several other fluid separation assembliesone at a time, wherein more of the hydrogen remaining in the gas mixturepermeates the permeable membranes and follows the path resulting in thispurified hydrogen passing to the permeate outlet. The remainder of thehydrogen depleted gas mixture exits through the discharge gas outletlocated at the opposite end of the module after flowing over the entirestack of fluid separation membrane assemblies. The disadvantage of thistype of conventional fluid separation assembly is that the fluidmembrane assemblies located at the bottom of the module are not fullyutilized. The hydrogen content of the feed gas mixture is depleted tothe point where the driving force (i.e., the partial pressure ofhydrogen) required to diffuse hydrogen through the permeable membranesof the fluid separation assemblies in the lower portion of the module isvery low.

Another conventional fluid separation configuration recycles thehydrogen depleted feed gas mixture. Recycling of the hydrogen depletedfeed gas mixture back into the feed stream allows this type of fluidseparation configuration to operate like a fully mixed reactor byexposing all of the fluid separation assemblies to a hydrogen feed gasmixture of identical composition. The disadvantage of this type of fluidseparation configuration is that it is expensive to recompress thehydrogen feed gas mixture which is necessary to overcome the pressurelosses as the hydrogen feed gas mixture moves through the module.

Thus, the need exists for a method and apparatus for inexpensively andeffectively separating a desired fluid from a fluid mixture that canreliably withstand high operating pressures and temperatures.

SUMMARY OF THE PRESENT INVENTION

The present invention provides a fluid separation module having groupsof multiple fluid separation assemblies that operate in parallel,creating a large permeable membrane surface area for the fluid mixtureto pass through. These groups of multiple fluid separation assembliescan then be assembled in a module in varying configurations or numbersdepending on the specific application.

The present invention further provides a fluid separation assemblyhaving a thin design that reduces the weight and volume of the fluidseparation assembly. This thin design allows the subassemblies to bepositioned in close proximity to each other in the module, whichincreases the packing density of the permeable membrane material (i.e.,increases the permeable membrane surface area per unit of total volumeof the fluid separation module).

The present invention provides the incorporation of turbulence inducingmechanisms in the feed channel to further increase the turbulence andmixing of the feed stream. These mechanisms may also be used as asupport structure for catalytic material. Having a specialized catalyticsurface in close proximity to the permeable membrane surface aids thekinetics of secondary chemical reactions to completion as the hydrogenis removed from the feed stream through the permeable membrane.

The present invention provides several feed redistribution plates thatdirect the feed flow through each group of multiple fluid separationassemblies that operate in parallel thus, reducing the number ofcomponents of the fluid separation module.

The present invention provides a mechanical seal on each of the feedredistribution plates to ensure that feed gases pass across the fluidseparation assemblies.

The present invention provides a fluid separation assembly having afluid permeable membrane and a wire mesh membrane support adjacent thefluid permeable membrane, wherein the wire mesh membrane support has anintermetallic diffusion bonding barrier.

The present invention further provides a method for separating a desiredfluid from a fluid mixture comprising providing a housing having a wall;providing a first plurality of fluid separation assemblies positionedadjacent one another; providing a second plurality of fluid separationassemblies positioned adjacent one another; positioning a plurality ofplates adjacent and between the first and second plurality of fluidseparation assemblies; forming a passageway defined by the plates andthe housing wall; passing fluid through the passageway and through thefirst plurality of fluid separation assemblies and through the secondplurality of fluid separation assemblies.

Other details, objects and advantages of the present invention willbecome more apparent with the following description of the presentinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

For the present invention to be readily understood and practiced,preferred embodiments will be described in conjunction with thefollowing figures wherein:

FIG. 1a is an isometric view of the fluid separation assembly of thepresent invention as assembled;

FIG. 1b is a top plan view of the fluid separation assembly shown inFIG. 1a;

FIG. 2 is an exploded isometric view of the fluid separation assembly ofthe present invention shown in FIG. 1a;

FIG. 3 is an exploded isometric view of the female permeable membranesubassembly of the present invention shown in FIG. 1a;

FIG. 4 is an exploded isometric view of the male permeable membranesubassembly of the present invention shown in FIG. 1a;

FIG. 5 is a sectional view of the fluid separation assemblies of thepresent invention shown in FIG. 1b and taken along line 5—5;

FIG. 6 is a sectional schematic view of a fluid separation module of thepresent invention having several groups of multiple fluid separationassemblies;

FIG. 7 is an enlarged schematic view of section A of the module shown inFIG. 6;

FIG. 8 is an isometric view of a feed redistribution plate of thepresent invention;

FIG. 9 is an isometric view of a turbulence screen of the presentinvention; and

FIG. 10 is a sectional view of multiple fluid separation assemblies anda turbulence screen of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will be described below in terms of apparatusesand methods for separation of hydrogen from a mixture of gases. Itshould be noted that describing the present invention in terms of ahydrogen separation assembly is for illustrative purposes and theadvantages of the present invention may be realized using otherstructures and technologies that have a need for such apparatuses andmethods for separation of a desired fluid from a fluid mixturecontaining the desired fluid.

It is to be further understood that the figures and descriptions of thepresent invention have been simplified to illustrate elements that arerelevant for a clear understanding of the present invention, whileeliminating, for purposes of clarity, other elements and/or descriptionsthereof found in a hydrogen separation assembly. Those of ordinary skillin the art will recognize that other elements may be desirable in orderto implement the present invention. However, because such elements arewell known in the art, and because they do not facilitate a betterunderstanding of the present invention, a discussion of such elements isnot provided herein.

FIGS. 1a, 1 b and 2 illustrate one embodiment of the fluid separationassembly 10 of the present invention, wherein FIG. 2 is an exploded viewof the fluid separation assembly 10 shown in FIG. 1a. The fluidseparation assembly 10 comprises first membrane retainers 12, a femalemembrane subassembly 14, a first membrane gasket 16, a first wire meshmembrane support 18, second membrane retainers 20, a slotted permeateplate 22, a permeate rim 24, a second wire mesh membrane support 28, asecond membrane gasket 30 and a male membrane subassembly 32. In oneembodiment, the first retainers 12 may be substantially flat membershaving four sides wherein two opposing sides are linear and the othertwo opposing sides are curvilinear such that the periphery correspondsto the peripheries of the female and male membrane subassemblies 14 and32 and the thickness of the first retainers 12 is between approximately0.001 inches and 0.060 inches. The first membrane retainers 12 havecentrally disposed openings 13 and 35. The first membrane retainers 12may be made from Monel 400 (UNS N 04400); however, other materials thatare compatible with the welding process, discussed below, may also beused. It will also be appreciated that the first retainers 12 may haveother desired shapes and other thicknesses than those illustratedwithout departing from the spirit and scope of the present invention.

FIG. 3 is an exploded view of the female permeable membrane subassembly14. In this embodiment, female membrane subassembly 14, comprises afemale gasket seat 36, a hydrogen permeable membrane 38, an innerdiameter membrane gasket 40 and a center support washer 42. In thisembodiment, the female gasket seat 36 is a substantially flat ringmember 44 having raised faces 46 a and 46 b extending around the ringmember 44 and a centrally disposed opening 45. The raised faces 46 a and46 b are sized and proportioned to form a channel 47 which may accept agasket 115, discussed below in connection with FIGS. 6-9, such that whenthe gasket 115 is compressed, it will not extrude and thus, it will becontained within the channel 47. It will be appreciated that there maybe other geometries of gasket seats specific to other gasketconfigurations or materials that may be used without departing from thespirit and the scope of the present invention. The female gasket seat 36may be made from Monel 400; however, other materials such as nickel,copper, nickel alloys, copper alloys, or other alloys that provide forcompatible fusion with the chosen permeable membrane material duringwelding may be used.

In this embodiment, the hydrogen permeable membrane 38 is asubstantially planar member having two opposing sides 41 which aresubstantially linear, two other opposing sides 43 that are curvilinear,opposing surfaces 48 and a centrally disposed circular opening 50. Theinner diameter membrane gasket 40 is a flat ring member having acentrally disposed opening 51. The center support washer 42 is a flatring member having a centrally disposed opening 53. The inner diametermembrane gasket 40 and the center support washer 42 may be made of Monel400 (UNS N 04400); however, other materials such as nickel, copper,nickel alloys, copper alloys, or other alloys that provide forcompatible fusion with the chosen permeable membrane material or alloyduring welding may be used.

Referring back to FIG. 2, in this embodiment, the first and secondmembrane gaskets 16 and 30 are each a substantially flat member havingcentrally-disposed openings 55 and 57, respectively. Similar to thefirst retainers 12 and the hydrogen permeable membrane 38, the first andsecond membrane gaskets 16 and 30 have four sides, wherein two opposingsides are substantially linear and two other opposing sides arecurvilinear. In this embodiment, the first and second membrane gaskets16 and 30 may be made from Monel 400 alloy (UNS N 004400), nickel,copper, nickel alloys, copper alloys or other precious alloys or otheralloys compatible with the weld that is used to join the components ofthe fluid separation assembly 10 and which is discussed below. The firstand second membrane gaskets 16 and 30 may have a thickness of betweenapproximately 0.0005 inches to 0.005 inches. However, other gasketthicknesses could be employed.

Also in this embodiment, the first and second wire mesh membranesupports 18 and 28 are planar members having centrally disposed openings52 and 54, respectively. The wire mesh membrane supports 18 and 28 eachhave four sides, wherein two opposing sides are linear and the other twoopposing sides are curvilinear. The wire mesh membrane supports 18 and28 may be made from 316L stainless steel alloy with a mesh count ofbetween approximately 19 to 1,000 mesh per inch, wherein the mesh countis chosen to be adequate to support the hydrogen permeable membranes 38and 62 (FIGS. 3 and 4). The style of woven mesh may include a standardplain square weave, twill square weave, rectangular plain or twillweave, or triangular plain or twill weave. One example of a mesh countthat may be used is 49 mesh per inch. The wire mesh membrane supports 18and 28 may be made of steel alloys, stainless steel alloys, nickelalloys or copper alloys. The wire mesh may be coated with a thin filmthat prevents intermetallic diffusion bonding (i.e., an intermetallicdiffusion bonding barrier). The intermetallic diffusion bonding barriermay be a thin film containing at least one of an oxide, a nitride, aboride, a silicide, a carbide, or an aluminide and may be applied usinga number of conventional methods, including but not limited to, physicalvapor deposition (PVD), chemical vapor disposition, and plasma enhancedvapor deposition. For example, the method of reactive sputtering, a formof PVD, can be used to apply a thin oxide film to the wire mesh membranesupports 18 and 28. A variety of oxides, nitrides, borides, silicides,carbides and aluminides may also be used for the thin film as well asany thin films that will be apparent to those of ordinary skill in theart. Using this form of PVD results in a dense amorphous thin filmhaving approximately the same mechanical strength as the bulk thin filmmaterial.

Also in this embodiment, the second membrane retainers 20 each are asubstantially flat member. The second membrane retainers 20 have foursides, wherein two opposing sides are substantially linear and the othertwo opposing sides are curvilinear. One retainer 20 has a centrallydisposed opening 59 and the other retainer 20 has a centrally disposedopening 60. See FIG. 2. These retainers 20 may be the same thickness asthe first and second wire mesh membrane supports 18 and 28. The secondmembrane retainers 20 may be made from a material that is compatiblewith the weld, discussed below, such as Monel 400 (UNS N 004400) andnickel, copper, nickel alloys, copper alloys, precious metals or alloys,or other alloys that provide for compatible fusion with the chosenmembrane material or alloy during welding may be used.

In this embodiment, the slotted permeate plate 22 is a steel platehaving a plurality of slots 56 extending radially and outwardly from acentrally disposed opening 58 in the direction of the periphery of theslotted permeate plate 22. The number of slots 56 in a slotted permeateplate 22 may range from approximately 10 to 72. However, other suitableslot densities may be employed. The permeate plate rim 24 is asubstantially flat member having a centrally disposed opening 63 thatreceives the slotted permeate plate 22, wherein the opening 63 of theinner periphery is larger than the outer periphery of the slottedpermeate plate 22 allowing for a gap at 63 between the slotted permeateplate 22 and the permeate plate rim 24. See FIG. 5. The shape of theslotted permeate plate 22 is similar to the other components of thefluid separation assembly in that it has four sides, wherein twoopposing sides are substantially linear and the other two opposing sidesare curvilinear. The permeate plate rim 24 is made from Monel 400 (UNS N04400); however, other materials can also be used such as nickel,copper, nickel alloys, copper alloys, precious metals or alloys or otheralloys that provide for compatible fusion with the chosen membranematerial or alloy during welding.

FIG. 4 is an exploded view of the male permeable membrane subassembly32. The male membrane subassembly 32 comprises a male gasket seat 61, ahydrogen permeable membrane 62, an inner diameter membrane gasket 64,and a center support washer 66. The hydrogen permeable membranes 38 and62 may be made from at least one hydrogen permeable metal or an alloycontaining at least one hydrogen permeable metal, preferably selectedfrom the transition metals of groups VIIIA or VIIIB of the periodictable. The hydrogen permeable membrane 62, the inner diameter membranegasket 64, and the center support washer 66 are similar in structure tothe hydrogen permeable membrane 38, the inner diameter membrane gasket40 and the center support washer 42, respectively, discussed above inconnection with FIG. 3. The hydrogen permeable membrane 62 has acentrally disposed opening 81. The male gasket seat 61 is asubstantially planar ring member 68 having a circular protuberance 70extending around a centrally disposed opening 72. In this embodiment,the female gasket seat 36 and the male gasket seat 61 are made of a highstrength alloy material that is compatible with the weld such as Monel400. The inner diameter membrane gaskets 40 and 64 are made from thesame materials as the first and second outer diameter membrane gaskets16 and 30, discussed above.

FIG. 5 is a cross-sectional view of the assembled fluid separationassembly 10 of the present invention. When assembling the components ofthe fluid separation assembly 10 shown in FIGS. 2-4, the female membranesubassembly 14 and the male membrane subassembly 32 are initiallyassembled. The female gasket seat 36 (FIG. 3), the permeable membrane38, the inner diameter membrane gasket 40 and the center support washer42 are placed adjacent one another such that their central disposedopenings 45, 50, 51 and 53, respectively, are coaxially aligned and forma portion of a conduit 80. A first weld 71 (FIG. 5) is placed at theopenings thereof. The first weld 71 takes the form of a weld beadcreating a hermetic seal between the female gasket seat 36, thepermeable membrane 38, the inner diameter membrane gasket 40 and thecenter support washer 42. The weld 71 can be effected by a number ofcommercially available technologies, including but not limited to,laser, electron beam, and tungsten inert gas (TIG) welding. Alternativejoining technologies such as brazing or soldering may also be employedwith the desired result being a gas tight bond between the gasket seat36 and the permeable membrane 38. Likewise, the components of the malemembrane subassembly 32 (FIG. 4), which include the male gasket seat 61,the permeable membrane 62, the inner diameter membrane gasket 64 and thecenter support washer 66 are also placed adjacent one another such thattheir centrally disposed openings 72, 81, 83 and 84 are coaxiallyaligned with each other forming another portion of conduit 80 and asecond weld bead 73 (FIG. 5) is placed around the circumference of theopenings 72, 81, 83 and 84 thereof. As stated above, the weld 73 can beeffected by a number of commercially available joining technologies,including but not limited to, laser, electron beam, and tungsten inertgas (TIG) welding.

After the components of the female membrane subassembly 14 and thecomponents of the male membrane subassembly 32 have each been connectedby the welds 71 and 73, respectively, they are assembled with the othercomponents described above to form the fluid separation assembly 10. Asshown in FIG. 2, the first and second retainer members 12 and 20, thefemale and male membrane subassemblies 14 and 32, the first and secondouter diameter gaskets 16 and 30, the first and second wire meshmembrane supports 18 and 28, the slotted permeate plate 22 and thepermeate rim 24 are aligned such that their centrally disposed openingsare coaxially aligned and form conduit 80. As shown in FIG. 5, thesecomponents are retained in that configuration by placing a weld 74 atthe outer periphery of the first and second retainer members 12 and 20,the female and male membrane subassemblies 14 and 32, the first andsecond outer diameter membrane gaskets 16 and 30, and the permeate rim24. Alternatively, these parts could be assembled such that theircentrally disposed openings are coaxially aligned, as shown in FIG. 5,and connected to one another by performing a brazing or solderingoperation at the outer periphery of the first and second retainermembers 12 and 20, the female and male membrane subassemblies 14 and 32,the first and second outer diameter membrane gaskets 16 and 30 and thepermeate rim 24. A space at 63 (FIG. 5) between the slotted permeateplate 22 and the permeate rim 24 permits expansion and contraction ofthe components of the fluid separation assembly 10 resulting from thechange in temperature. Assembled, the fluid separation assembly 10 mayhave a thickness ranging from 0.010 inches to 0.125 inches, dependingupon the thicknesses of the components employed.

FIGS. 6 and 7 illustrate a fluid separation module 85 of the presentinvention employing several groups of multiple fluid separationassemblies 10, wherein FIG. 7 is an enlarged section A of the module 85.For clarity, the number of fluid separation assemblies 10 shown in FIG.7 has been reduced from ten to four between each successiveredistribution plate 102 a, 102 b, and 102 c. To more clearly representthe assembly of the module 85, the fluid separation assemblies 10 areshown in FIG. 7 without the details shown in FIG. 5. The fluidseparation module 85 substantially comprises a housing 100, a pluralityof feed redistribution plates 102 a-102 j, several groups of multiplefluid separation assemblies 104 a-104 i, a plurality of turbulencescreens 106, a plurality of guide rods 109, and a compression mechanism108. The compression mechanism 108 comprises a compression cap 160, hightemperature belleville type springs 162 and a spring guide 164. Thesecomponents of the compression mechanism 108 are standard in theindustry. The housing 100 substantially comprises a cylindrical body, apermeate end plug 112 a, a feed end plug 112 b, compressible gaskets 118a and 118 b, a lock ring 116 a, a lock ring 116 b, a feed gas inlet 91,a permeate outlet 90 and a discharge gas outlet 93. The housing 100 maybe made of carbon, alloy, heat and corrosion resistant steels, such asstainless steel or other alloys; however, a variety of metals may alsobe used, as will be apparent to one of ordinary skill in the art. Avariety of conventional module housings can also be employed with thepresent invention.

FIG. 8 is an isometric view of a feed redistribution plate 102 of thepresent invention. The feed redistribution plates 102 each have acurvilinear portion 140, a substantially linear portion 142, a feedredistribution sealing ring 130, and a female gasket member 132 and amale gasket (not shown) which are welded to redistribution plate 102.The feed redistribution sealing ring 130 fits inside the slot 136 andaround the curvilinear portion 140 of the feed redistribution plate 102.The male gasket member and female gasket member 132 may take the sameform as the male and female gasket members 61 and 36, shown in FIGS. 4and 3, respectively. The feed redistribution plate 102 also has holes138 which serve as alignment holes for the guide rods 109 such that theguide rods 109 are received therein to maintain the radial orientationof the redistribution plates 102, and the fluid separation assemblies 10in the housing 100. The guide rods 109 may be sized and proportionedsuch that they are received by recesses in the end plug 112 a (FIG. 8).The feed redistribution plate 102 may be made from stainless alloy orother suitable high temperature material.

FIG. 9 is an isometric view of a turbulence screen 106 of the fluidseparation module 85 of the present invention; and FIG. 10 is asectional view of multiple fluid separation assemblies 10 and aturbulence screen 106 of the present invention. The to turbulence screen106 has a centrally disposed opening 150 and four sides, wherein twoopposing sides 152 are substantially linear and the other two opposingsides 154 are curvilinear. The turbulence screen 106 is a plain wovenscreen with a thickness substantially the same as the opening of theflow channel between fluid separation assemblies is utilized.Conventional woven mesh may be used for the economic manufacture of theturbulence screens 106, but other materials that promote turbulencecould also be selected, such as refractory or high temperature cloths,fibers, mats, felts, or papers. Reticulated ceramics and other types ofwoven or mat type metal materials (i.e., steel wool) would also serve asa suitable material for the turbulence screen 106. These turbulencescreens 106 also may be coated with catalytic material to drivesecondary chemical reactions to completion in close proximity to thehydrogen permeable membrane surfaces, without actually contacting thepermeable membrane surfaces 48 and 62 and causing damage. The selectionof the material and construction should be compatible with the type ofcatalytic material employed. Catalytic materials may be chosen from avariety of commercially available catalysts. The choice of catalyticmaterial is dependent upon the required operating parameters of thereaction (i.e., pressure, temperature, type and concentration of theconstituents in the feed stream) as well as the desired reaction. Thecatalytic materials could be applied directly to the turbulence screen106, or indirectly using an intermediate coating material to improveadhesion and prevent spalling of the catalytic material during operationof the module 85. The main criteria for the selection of the material ofthe turbulence screen 106 is that the material be thermally stable andrigid enough so that it will not deform and possibly damage thepermeable membranes 48 and 62.

Referring back to FIGS. 6 and 7, when assembling the fluid separationmodule 85, the end plug 112 a may be welded to the female gasket seat114. Suitable plumbing fittings (not shown), such as a compression orface seal type, may be welded to the permeate port outlet 90 anddischarge outlet port 93. A pliable high-temperature gasket 118 a isthen installed onto the end plug 112 a. The gasket 118 a may be a moldedor pressed unitary flat wound material, a rectangular or squarecross-sectional woven or non-woven packing material, or a multiple cutring of sheet-type gasket material that is fitted onto the shoulder ofthe end plug 112 a to create a compression-type seal. Other types ofmechanical seals, such as metal o-rings, metal c-section seals, or softmetal seals, may also be used.

After the gasket 118 a is in place, the end plug 112 a is inserted intothe module body 110 and a threaded lock ring 116 a is screwed into theend of the module housing 100. The module 85 is then placed into a press(not shown) and a mechanical force is applied to the end plug 112 aforcing it down against the lock ring 116 a thus, compressing the gasket118 a and forcing the gasket 118 a in an outward radial directionagainst the wall 110 of the module 85, creating a seal.

One feed redistribution plate 102 a is inserted into the housing 100adjacent the female seat 114. The sealing ring 130 of the feedredistribution plate 102 a is compressed and forms a fluid tight sealwith the housing 100. The grooves 136 cut into the outer periphery ofthe redistribution plates 102 allow the sealing rings 130 to becompressed. Once the redistribution plates 102 are lowered into thehousing 100, the compression on the sealing rings 130 are released,allowing them to contact the wall 110 of the housing 100. The malegasket seat on the underneath sides of the redistribution plates 102 arein contact with a fibrous gasket 115 (FIG. 7) that is received withinthe female gasket seat 114. It will be appreciated that other mechanicalseals employing different geometries and different materials may be usedto effect a fluid-tight seal.

After the redistribution plate 102 a is in place, a plurality of thefluid separation assemblies 104 a and turbulence screens 106 positionedbetween each of the fluid separation assemblies 104 a may then beassembled into the module 85. The guide rods 109 are inserted into theholes 138 of the redistribution plate 102 a. The centrally disposedopenings of each of the turbulence screens 106, the fluid separationassemblies 10 and the feed redistribution plates 102 are coaxiallyaligned. The turbulence screens 106 are added between each pair of fluidseparation assemblies 10 to promote turbulent flow of the feed gases andinsure that hydrogen rich feed gas is continuously fed to the membranesurface. The turbulence screens 106, shown in FIGS. 6, 7 and 9, contactthe planar surfaces of the female gasket seat 44 (FIG. 5) and the malegasket seat 68 when the module 85 (FIG. 6) is constructed. Theturbulence screens 106 are held in place by the first membrane retainers12 of the fluid separation assemblies 10 that are adjacent to eachturbulence screen 106. A turbulence screen 106 is positioned betweenfluid separation assemblies 10, as shown in FIG. 10, when the fluidseparation assemblies 10 are stacked adjacent to one another to creategroups of multiple fluid separation assemblies 104 a-104 i (FIGS. 6 and7).

The turbulence screens 106 also serve as a substrate for the applicationof reaction catalysts that will prompt a secondary reaction adjacent tothe permeable membrane surfaces 48 and 62. One example of a catalyticmaterial that may be used for methanol steam reforming or water-gasshift reactions is a material comprised of Cu/ZnO/A1203, wherein thedesired reaction to take place would be dependent upon the operatingparameters employed. When a hydrogen producing reaction is carried outin this manner, the reaction kinetics are driven to completion by thecontinuous removal of hydrogen from the feed stream by the hydrogenpermeable membranes 48 and 62. An example of this type of reaction isthe water-gas shift reaction, which is denoted as:

H₂O_(vapor)+CO⇄H₂+CO₂

As the water vapor and carbon monoxide react to form hydrogen and carbondioxide in the presence of a suitable catalyst, hydrogen is continuallybeing removed by the hydrogen permeable membranes 48 and 62 thus,allowing a substantially complete reaction. This type of reaction iscommon in hydrogen rich reformate streams, where both water vapor andcarbon monoxide are present. Catalytic materials may be chosen from avariety of commercially developed catalysts, wherein the selection ofthe catalytic material would be dependent upon the required operatingparameters of the reaction (i.e., pressure, temperature, type andconcentration of the constituents in the feed stream) as well as thedesired reaction to take place. The catalytic materials may be applieddirectly to the turbulence screen 106, or indirectly using anintermediate coating material to improve adhesion and prevent spallingof the catalytic material during operation.

The redistribution plates 102 are positioned on the female and malegasket seats 36 and 61 in such a manner that they are positionedequidistant from the planar surface of the permeable membrane assemblies14 and 32 in successive fluid separation assemblies 10. Theredistribution plates 102 are not fixedly connected to the gasket seats36 and 61, but rather are received by the channel 47 of the femalegasket seat 36 and the raised face 70 of the male gasket seat 61. Thereis sufficient clearance between slot 136 and the sealing ring 130 of theredistribution plate 102 such that the redistribution plate 102 and thefluid separation assemblies 10 are positioned inside the wall 110 of thehousing 100 independently of the position of the fluid separationassemblies 10. Each redistribution plate 102 has opening 89 therein.

Several groups of multiple fluid separation assemblies 104 b-104 i (FIG.6) are stacked within the module 85, wherein the feed redistributionplates 102 b-102 j separate the groups of fluid separation assemblies104 b-104 i and turbulence screens 106 separate successive fluidseparation assemblies 10. The fluid separation assemblies 10 are alignedone with the other such that each of the conduits 80 (FIG. 5) of thefluid separation assemblies 10 form a portion of channel 180. Theassembly of the module 85 continues by alternatively stacking a gasket115, multiple fluid separation assemblies 104 having turbulence screens106 positioned between successive fluid separation assemblies 10, andfeed redistribution plates 102 until the desired number of groups ofmultiple fluid separation assemblies 104 have been stacked in the module85. Please note that the redistribution plate 102 b is assembled in thesame way as the redistribution plate 102 a, with the exception that itis rotated 180 degrees relative to the first redistribution plate 102 a.This alternating orientation of the redistribution plates 102 along thestack of fluid separation assemblies 104 a-104 i creates a fluidpassageway C (FIG. 7) that directs the feed gas over each group of fluidseparation assemblies 10. It should also be noted that the number offluid separation assemblies 10 in the multiple fluid separationassemblies 104 a-104 i may be assembled in different quantities. In thisembodiment, equal numbers of fluid separation assemblies 10 comprisingthe multiple fluid separation assemblies 104 have been placed betweeneach successive redistribution plate 102 for purposes of illustrationonly. The number of fluid separation assemblies 10 between eachsuccessive redistribution plate 102 may be reduced or increased tooptimize the performance of the fluid separation assemblies 10 at eachsuccessive stage in the module 85. Altering the number of fluidseparation assemblies 10, and thus the total permeable membrane areabetween each successive redistribution plate 102, allows the overallperformance of the hydrogen separation module 85 to be maximized withrespect to the total permeable membrane area required for a given fluidseparation application. For example, a larger number of fluid separationassemblies 10 may be positioned together at the feed end of the module85, where the feed stock gas is highest in hydrogen content and areduced number of fluid separation assemblies 10 may be positioned atthe raffinate end of the module 85, where the hydrogen depleted feed gasexits.

When the last redistribution plate 102 j is assembled in the module 85,the compression mechanism 108 is placed on the redistribution plate 102j. The belleville springs 162 are sized such that at full compression,supplies a compressive load sufficient to maintain a positive sealingforce on the gaskets 115 positioned between the fluid separationassembles 104 a-104 i in the module 85. When the gaskets 115 arecompressed, they also provide a small amount of give to compensate forthe different coefficients of thermal expansion inherent to thedifferent materials used in the module 85. As the module 85 thermallycycles between ambient and operating temperatures, the components withinthe module 85 are able to expand and contract. This small amount of givealso helps compensate for any additional compression of the gaskets 118a and 118 b that may occur over time.

With the compression mechanism 108 in place, the end plug 112 b isfitted with a gasket 118 b identical to the gasket 118 a, and is loweredinto the module 85. A suitable plumbing fitting (not shown), such as acompression or face seal type fitting is welded into the inlet port 91.The lock ring 116 b is then screwed into the module 85 to a point whereit is flush with the end of the housing 100. A setscrew 175 is insertedinto the threaded compression screw hole 172. As this setscrew 175 istightened, it contacts the compression cap 160 and forces the end plug112 b upwards against the lock ring 116 b. This results in the gasket118 b being forced outwardly in a radial direction against the wall 110,thus creating a fluid-tight seal. At the same time that the end plug 112b is being forced upwards, the setscrew 175 is compressing thebelleville springs 162 and thus, maintaining a compressive force on thegaskets 115 within the module 85. After the setscrew 175 has beentightened to the required torque necessary for fully compressing thebelleville springs 162, a sealing gasket (not shown) is placed in therecess surrounding the threaded screw hole 172. The cap 170 is thenscrewed into the hole 172 and tightened to create a positive seal withthe sealing gasket positioned in the recess surrounding the hole 172 andthe end plug 112 b.

During operation, the hydrogen rich feed gas is admitted into the inletport 91 and travels in a serpentine fashion through passageway C in themodule 85 where the feed gas encounters multiple fluid separationassemblies 104 a-104 i. Specifically, pure hydrogen is first diffusedthrough the permeable membrane of each fluid separation assembly 10comprising multiple fluid separation assemblies 104 i and is collectedin a central permeate channel 180. The permeate hydrogen exits themodule 85 through the permeate outlet 90, while the hydrogen depletedmixture exits through the discharge outlet 93. Referring to FIG. 5, whenseparating the hydrogen from the feed gas that includes hydrogen, thefeed gas is directed towards the permeable membranes 38 and 62 of thefemale membrane subassembly 14 and the male membrane subassembly 32,respectively, in the directions D and E. When the feed gas containinghydrogen contacts the hydrogen permeable membranes 38 and 62, thehydrogen permeates through the permeable membranes 38 and 62, passesthrough the first and second wire mesh membrane supports 18 and 28 andenters the slotted permeate plate 22 where the hydrogen enters slots 56and is directed toward the central axis H by the passageways formed bythe slots 56. The central openings of the components of the fluidseparation assembly 10 form the conduit 80, which forms a portion of thechannel 180 such that the purified hydrogen is collected and transportedto the permeate outlet 90. The conduit 80 may have a diameter of betweenapproximately 0.25 inches and 1 inch. The diameter is determined by thecomponents of the fluid separation assembly 10 and by the desire thatthe hydrogen flow be substantially unimpeded. The non-hydrogen gases inthe gas mixture are prevented from entering the fluid separationassembly 10 by the fluid permeable membranes 38 and 62. The remainder ofthe hydrogen depleted feed gas is directed around the exterior of thefluid separation assembly 10 and continues along the passageway C to thenext set of multiple fluid separation assemblies 104 h, 104 g, 104 f,104 e, 104 d, 104 c, 104 b and 104 a.

Although the present invention has been described in conjunction withthe above described embodiment thereof, it is expected that manymodifications and variations will be developed. This disclosure and thefollowing claims are intended to cover all such modifications andvariations.

What is claimed is:
 1. A method for separating a desired fluid from a fluid mixture, comprising: a) providing a housing having a wall; b) providing a first plurality of fluid separation assemblies positioned adjacent one another; c) providing a second plurality of fluid separation assemblies positioned adjacent one another; d) positioning a plurality of plates adjacent and between said first and second plurality of fluid separation assemblies, thereby forming a passageway defined by said plates and said housing wall; and e) passing fluid through said passageway and through said first plurality of fluid separation assemblies and through said second plurality of fluid separation assemblies, wherein each fluid separation assembly of said first and second plurality of fluid separation assembly comprises a fluid permeable membrane having a centrally disposed opening and a wire mesh membrane adjacent said fluid permeable membrane, said wire mesh membrane having an intermetallic diffusion barrier.
 2. A method for separating a desired fluid from a fluid mixture, comprising: a) providing a housing having a wall; b) providing a first plurality of fluid separation assemblies positioned adjacent one another; c) providing a second plurality of fluid separation assemblies positioned adjacent one another; d) positioning a plurality of plates adjacent and between said first and second plurality of fluid separation assemblies, thereby forming a passageway defined by said plates and said housing wall; and e) passing fluid through said passageway and through said first plurality of fluid separation assemblies and through said second plurality of fluid separation assemblees, wherein said fluid separation assemblies of said first and second pluralities of fluid separation assemblies comprise: i) a permeate plate having a first surface, a second surface, a fluid outlet and fluid passageways extending from said first surface and said second surface to said fluid outlet; ii) first and second wire mesh membranes adjacent said first surface and said second surface of said permeate plate, respectively, each of said first and second wire mesh membranes comprising a wire mesh having a coating that is an intermetallic diffusion bonding barrier and having an opening aligned with said fluid outlet of said permeate plate; and iii) first and second fluid permeable membranes, said first fluid permeable membrane adjacent a surface of said first wire mesh membrane opposite said permeate plate, said second fluid permeable membrane adjacent a surface of said second wire mesh membrane opposite said permeate plate, each of said first and second permeable membranes having an opening aligned with said fluid outlet.
 3. A fluid separation module, comprising: a housing having a wall; a first plurality of fluid separation assemblies within said housing, each of said first plurality of fluid separation assemblies are adjacent one another; a second plurality of fluid separation assemblies within said housing, each of said second plurality of fluid separation assemblies are adjacent one another; a plurality of plates within said housing, said plurality of plates positioned between and separating said first plurality of fluid separation assemblies from said second plurality of fluid separation assemblies; and a fluid passageway defined by said plurality of plates and said housing wall, wherein each fluid separation assembly comprises a first fluid permeable membrane having a centrally disposed opening and a first wire mesh membrane adjacent said first fluid permeable membrane, said first wire mesh membrane having an intermetallic diffusion barrier.
 4. The fluid separation module of claim 3, wherein said first wire mesh membrane has a centrally disposed opening which is in alignment with said first fluid permeable membrane opening.
 5. The fluid separation module of claim 4, wherein the opening of the wire mesh membrane and the opening of said fluid permeable membrane are coaxially aligned.
 6. The fluid separation module according to claim 3, wherein said barrier is a thin film containing at least one of the group consisting of nitrides, oxides, borides, silicides, carbides and aluminides.
 7. The fluid separation module according to claim 3, wherein said barrier is a thin film containing one of an oxide and a nitride.
 8. The fluid separation module according to claim 3, wherein said first wire mesh membrane has a mesh count ranging between approximately 19 to 1000 mesh per inch.
 9. The fluid separation module according to claim 3, further comprising a slotted permeate plate adjacent to said first wire mesh membrane.
 10. The fluid separation module according to claim 3, said fluid separation assemblies further comprising: a. a permeate plate having a first surface, a second surface, a centrally disposed fluid outlet and fluid passageways extending from said first surface and said second surface to said fluid outlet; b. a second wire mesh membrane adjacent said second surface of said permeate plate, said second wire mesh membrane comprising a wire mesh having a coating that is an intermetallic diffusion bonding barrier and having an opening aligned with said fluid outlet of said permeate plate, and wherein said first wire mesh membrane is adjacent said first surface of said permeate plate; and c. a second fluid permeable membrane adjacent a surface of said second wire mesh membrane opposite said permeate plate, wherein said first fluid permeable membrane is adjacent a surface of said first wire mesh membrane opposite said permeate plate, each of said first and second permeable membranes having an opening aligned with said fluid outlet.
 11. The fluid separation module according to claim 10, wherein said permeate plate, said second wire mesh membrane and said second fluid permeable membrane each also have a centrally disposed opening and each of said centrally disposed openings are coaxially aligned and form a central conduit.
 12. The fluid separation module according to claim 10, wherein each of said fluid permeable membranes further comprises a gasket seat, a membrane gasket, and a washer to form first and second membrane subassembly, wherein said gasket seats, said membrane gaskets and said washers are connected to said fluid permeable membranes.
 13. The fluid separation module according to claim 12, further comprising a weld bead connected to each of said first and second membrane subassemblies.
 14. The fluid separation module according to claim 13, further comprising first retainers, one of said first retainers connected to each of said fluid permeable membranes.
 15. The fluid separation module according to claim 14, further comprising second retainers adjacent said permeate plate.
 16. The fluid separation module according to claim 13, further comprising first retainers and second retainers, wherein said first retainers and said second retainers are adjacent each of said fluid permeable membranes.
 17. The fluid separation module according to claim 13, further comprising gaskets, one of said gaskets adjacent each of said wire mesh membranes.
 18. The fluid separation module according to claim 3, wherein said first wire mesh membrane is made from stainless steel.
 19. The fluid separation module according to claim 3, wherein said plurality of plates are a substantially planar member having a gasket connected at the periphery of said plate.
 20. The fluid separation module according to claim 19, wherein each of said plurality of plates has a groove extending around a portion of the periphery of each of said plurality of plates, and said gasket is received within said grooves.
 21. The fluid separation module according to claim 3, wherein said plurality of plates have a curved portion and a linear portion.
 22. The fluid separation module according to claim 3, wherein said housing is substantially cylindrical and said plurality of plates has a surface area that is less than a cross-sectional area of said housing.
 23. The fluid separation module according to claim 3, wherein each of said plurality of plates defines a plurality of holes therethrough.
 24. The fluid separation module according to claim 23, further comprising a plurality of guide rods that are received by said holes.
 25. The fluid separation module according to claim 23, wherein each of said plurality of plates has first and second gaskets connected thereto.
 26. The fluid separation module according to claim 25, wherein said first and second gaskets have male and female connectors, respectively.
 27. The fluid separation module of claim 3, wherein the first wire mesh membrane and the first fluid permeable membranes are substantially planar.
 28. The fluid separation module according to claim 3, further comprising one or more additional pluralities of fluid separation assemblies within said housing, said fluid separation assemblies of each of said additional pluralities of fluid separation assemblies being adjacent each other.
 29. A fluid separation module, comprising: a housing having a wall; a first plurality of fluid separation assemblies within said housing, each of said first plurality of fluid separation assemblies are adjacent one another; a second plurality of fluid separation assemblies within said housing, each of said second plurality of fluid separation assemblies are adjacent one another; a plurality of plates within said housing, said plurality of plates positioned between and separating said first plurality of fluid separation assemblies from said second plurality of fluid separation assemblies; and a fluid passageway defined by said plurality of plates and said housing wall; said fluid separation assemblies comprising: a. a permeate plate having a first surface, a second surface, a fluid outlet and fluid passageways extending from said first surface and said second surface to said fluid outlet; b. first and second wire mesh membranes adjacent said first surface and said second surface of said permeate plate, respectively, each of said first and second wire mesh membranes comprising a wire mesh having a coating that is an intermetallic diffusion bonding barrier and having an opening aligned with said fluid outlet of said permeate plate; and c. first and second fluid permeable membranes, said first fluid permeable membrane adjacent a surface of said first wire mesh membrane opposite said permeate plate, said second fluid permeable membrane adjacent a surface of said second wire mesh membrane opposite said permeate plate, each of said first and second permeable membranes having an opening aligned with said fluid outlet.
 30. The fluid separation assembly of claim 29, wherein said openings of said fluid permeable membranes and said wire mesh membranes and said outlet of said permeate plate are centrally disposed and coaxially aligned to form a central conduit.
 31. The fluid separation assembly of claim 30, wherein said fluid permeable membranes, said wire mesh membranes and said permeate plate are substantially flat and ring-shaped said permeate plate includes slots defining said fluid passageways, and said slots are radially disposed.
 32. The fluid separation assembly of claim 29, further comprising a hermetic seal peripheral to said fluid permeable membranes, said wire mesh membranes, and said permeate plate.
 33. The fluid separation assembly of claim 32, wherein each of said fluid permeable membranes further comprises a gasket seat, a membrane gasket, and a washer disposed about said opening to form a first and second membrane subassembly, wherein said gasket seats, said membrane gaskets and said washers are connected to said fluid permeable membranes.
 34. The fluid separation assembly of claim 33, wherein said hermetic seal comprises a weld bead connected to each of said first and second membrane subassemblies.
 35. The fluid separation assembly of claim 29, further comprising first retainers, one of said first retainers connected to each of said fluid permeable membranes.
 36. The fluid separation assembly of claim 35, further comprising second retainers adjacent said permeate plate.
 37. The fluid separation assembly of claim 29, further comprising first retainers, one of said first retainers adjacent each of said fluid permeable membranes.
 38. The fluid separation assembly of claim 29, further comprising gaskets, one of said gaskets adjacent each of said first and second wire mesh membranes.
 39. The fluid separation assembly of claim 29, wherein said fluid permeable membranes are selectively permeable to hydrogen.
 40. The fluid separation assembly of claim 29, wherein said fluid permeable membranes comprise palladium or a palladium alloy.
 41. The fluid separation assembly of claim 29, wherein said wire mesh membranes comprise stainless steel.
 42. The fluid separation assembly of claim 29, wherein the intermetallic diffusion bonding barrier contains a compound selected from the group consisting of oxides, nitrides, borides, silicides, carbides and aluminides.
 43. The fluid separation assembly of claim 29, wherein the intermetallic diffusion bonding barrier contains one of an oxide and a nitride. 